1. Field of the Invention
The present invention relates to a scroll compressor and, more particularly, to an oil supply device of a scroll compressor capable of reducing abrasion and a noise of a friction portion by supplying oil to an oldhamring key to perform a smooth lubricating operation on the rubbed portion, and thus enhancing reliability of a compressor.
2. Description of the Background Art
FIG. 1 is a sectional view of a scroll compressor in accordance with a conventional art.
The conventional scroll compressor includes: a casing 106 having a certain closed space, to which a suction pipe 102 for sucking a fluid and discharge pipe 104 for discharging a compressed fluid are connected, a driving unit 108 disposed at a lower portion of the casing 106 and generating a driving force; and a compressing unit 110 disposed at an upper portion of the casing 106 and connected to the driving unit 108 by a rotating shaft 112 to compress the fluid sucked into the suction pipe 102 according to rotation of the rotating shaft 112 and discharge it through the discharge pipe 104.
A main frame 114 for rotatably supporting the upper portion of the rotating shaft 112 and the compressing unit 110 is installed at the upper portion of the casing 106, and a lower frame 116 for rotatably supporting a lower portion of the rotating shaft 112 is installed at the lower portion of the casing.
The driving unit 108 includes a stator 122 fixed in a circumferential direction of the casing 106 and a rotor 124 disposed at an inner circumferential surface of the stator 122 and fixed at the rotating shaft 112. When power is applied to the stator 122, the rotor 124 is rotated according to interaction between the stator 122 and the rotor 124, rotating the rotating shaft 112.
The compressing unit 110 includes a fixed scroll 128 having a fixed wrap 126 in an involute shape and fixed at an upper portion of the casing 106, and a orbiting scroll 132 having an orbiting wrap 130 in the involute shape corresponding to the fixed wrap 126 to have a certain compression chamber 118 therebetween, orbitingly supported by the main frame 114, and orbiting when the rotating shaft 112 is rotated.
A discharge passage 136 is formed at the center of the fixed scroll 128 in order to discharge a fluid after being compressed in the compressing chamber 118 according to the interaction between the fixed wrap 126 and the orbiting wrap 130, and a check valve 138 is installed at an upper side of the discharge passage 136 in order to prevent backflow of discharged fluid.
A muffler 140 is mounted at an upper side of the fixed scroll 128 in order to reduce noise of a gas being discharged to the discharge passage 136, and an oldhamring 150 for preventing rotation of the orbiting scroll 132 is installed between the orbiting scroll 132 and the main frame 114.
A key home 160 is formed at intervals of 90° at an upper surface of the main frame 114, into which the oldhamring key of the oldhamring 150 is inserted.
FIG. 2 is a view of an upper surface of the main frame of the conventional scroll compressor and FIG. 3 is an enlarged view of a portion ‘A’ of FIG. 1.
The oil supply device includes a pumping unit 162 mounted at a lower side of the rotating shaft 112 and pumping oil stored at a lower portion of the casing 106 according to rotation of the rotating shaft 112; an oil supply passage 164 formed in a longitudinal direction at the rotating shaft 112 and supplying oil pumped by the pumping unit 162 to each friction portion; and n oil supply hole 166 formed at the main frame 114 and supplying oil from the oil supply passage 164 to a thrust bearing surface contacting between the orbiting scroll 132 and the main frame 114.
As for the oil supply hole 166, a first supply hole 168 is formed penetratingly in a horizontal direction at the main frame 114 and a second supply hole 170 is formed in a vertical direction at an upper surface of the main frame 114 so as to be connected with the first supply hole 168. An exposed portion of the first supply hole 168 is closed with rivet 172.
The conventional oil supply device constructed as described above operates as follows.
When power is applied to the stator 122, the rotor 124 is rotated according interaction between the stator 122 and the rotor 124 and the rotating shaft 112 fixed at the rotor 124 is rotated in a forward direction. Then, the orbiting scroll 132 is orbitingly moved according to the rotation of the rotating shaft 112 to interact with the fixed scroll 128 to compress the gas flowing into the compressing chamber 118. The compressed gas is introduced into the high pressure chamber 142 through the discharge passage 136, and then the gas introduced into the high pressure chamber is discharged externally through the discharge pipe 104.
When the compressor is driven, the oil supply device is driven to supply oil stored at the lower portion of the casing to each friction portion of the compressor, thereby making a lubricating operation.
In other words, when the rotating shaft is rotated, the pumping unit mounted at the lower end of the rotating shaft is operated to pump the oil stored at the lower portion of the casing. The pumped oil is delivered upwardly along the oil supply passage formed at the rotating shaft and supplied between the thrust bearing surface of the main frame and the thrust bearing surface of the orbiting scroll through the oil supply hole formed at the main frame, making a lubricating operation.
However, the oil supply device of the conventional scroll compressor has the following problems.
That is, when the oil supply hole is processed at the main frame, the first supply hole is formed in the horizontal direction, the second supply hoe is formed in the vertical direction, and then, the outer side of the first supply hole is riveted to be closed. Thus, its fabrication process is complicate and fabrication cost is high.
In addition, the oil supplied to the thrust bearing surfaces of the main frame and the orbiting scroll through the oil supply hole is not smoothly supplied to the key hole into which the oldhamring key is inserted, causing generation of abrasion and noise.
Moreover, the oil supplied to the thrust bearing surfaces of the main frame and the orbiting scroll through the oil supply hole cannot smoothly flow out, causing a problem that the supplied oil is retained.